Step 1: Preparation

Get some wood planks, I used some treated wood from the local DIY store but old pallets would work well for this. I had one 150mmx20mm plank, and some 50mmx20mm battens.

The design is based on a 3-4-5 right angle triangle which simplifies the math for the design. The planters are 200mm tall, and about the same depth at the top, the bottoms are about 150mm deep. I needed room for 4 so the ladder would need to be at least 800mm high, so it would be 600mm deep, and the longest side of the planks needs to be at least 1000mm. I cut them slightly longer to give a bit of room at the top, the plank is 2100mm long which is perfect.

To calculate the angle to cut use the 3-4-5 triangle to mark the shape on the plank at the centre and saw at the plank to give 2 equal lengths.

Step 2: Mark Lines for Planter Shelves

Mark up the places where the shelves will go, for 200mm between the shelves it would be 250mm between each mark along the edge, I added a bit to that to space them out, don't forget to allow room for the shelves too.

Then along the lines mark where you will drill for the screws to hold the shelves. Also mark where you will saw the top of the planks for where they rest against the wall, this line will be at a right angle to the shelves.

Do this on one plank, then lay one on top of the other with the bottoms lined up and drill through both, this will ensure the shelf holes are lined up on both planks, use a drillbit slightly larger than the screws you have. also saw off the top to the line marked.

Step 3: Shelves

Cut the battens to right length, my planters are 500mm wide so I added a bit to that and cut one batten, then used that one to mark where to cut the others so they would all match in length.

Drill pilot holes in the shelves to match with the ones drilled in the planks, this time use a drillbit smaller than the screws so they bite into the wood when you screw them in.

With all the shelves in it's pretty much done.

Step 4: Finished

I can't attach the ladder to the wall here so I added some supports using the leftover bits of wood, also would be worth adding some support in front and behind each planter to prevent the planters being knocked or blown off.

Put the planters on it and it's finished, now I just need some better plants.